Locking joint for concrete piles having joined sections

ABSTRACT

The present invention relates to a locking joint for concrete piles having joined sections. The facing end surfaces of the sections to be joined are made of metal and have outwardly projecting pins and/or openings arranged therein, the openings communicating with pin receiving spaces to receive a pin from a next section. The pin receiving spaces have metal walls and each pin has a transverse hole therethrough to receive a wedge device to be inserted through the hole in the pin through a bore projecting through the side of the pile section into which the pin is inserted, thereby to hold the ends of the pile sections in firm abutting relationship. The locking joint is mainly characterized in that the wedge device is held in locking position in the bore and in the transversally extending hole through the pin by locking means located in the bore adjacent the side surface of the pile section and on the wedge device itself.

United States Patent 11 1 '11 11 3,884,589 Liedholm May 20, 1975 1 1 LOCKING JOINT FOR CONCRETE PILES 198,975 12/1958 Sweden 61/56 HAVING JOINED SEQTIONS 749,631 1/1967 Canada 6l/53 [75] Inventor: Per Lledholm, Solna, Sweden Primary Examiner wemer H Schroeder [73] Assignee: Stabilator AB, Bromma, Sweden Assistant Examiner-Conrad L. Bennan [22] Filed: Feb. 6, 1973 Attorney, Agent, or FzrmAnthony A. O Brien [21] Appl. N0.: 330,123 [57] ABSTRACT The present invention relates to a locking joint for [30] Foreign Apphcauon Pnonty Data concrete piles having joined sections. The facing end Feb. 22, Sweden Surfaces of the ections to be joined are made of metal Mar. 21, Sweden and have outwardly projecting pin and/or opening arranged therein, the openings communicating with U-Se Cl. pin receiving paces to receive a pin from a next sec 85/88; 403/155; 403/355; 403/374; 03/3 tion. The pin receiving spaces have metal walls and [5 e each pin has a transverse hole therethrough to r ive Fleld of Search 316, 286, a wedge device to be inserted through the hole in the 355, 374, 61/53, pin through a bore projecting through the side of the 85/33, 5 N; 287/D1G- 7 pile section into which the pin is inserted, thereby to hold the ends of the pile sections in firm abutting relal References Cited tionship. The locking joint is mainly characterized in UNITED STATES PATENTS that the wedge device is held in locking position in the 1,397,101 11 1921 Kelly 287/135 bore in transversally extnding hole through 1,771,949 7/1930 Blanchard 287/135 the P y ocking means located in the bore adjacent FOREIGN PATENTS OR APPLICATIONS gelisiieitssfiiaillgface of the pile section and on the wedge 908,920 12/1960 United Kingdom 61/56 103,249 10/1941 Sweden 85/88 1 Claim, 2 Drawing Figures S i 1 6 E 2 r I S t a a 1 g '1 E S j 14 PATENTEI] HAY 2 0 i975 FIG I LOCKING JOINT FOR CONCRETE PILES HAVING JOINED SECTIONS The present invention relates to a locking joint for concrete piles having joined sections, the facing end surfaces of the pile sections being made of metal and being provided with outwardly protruding pins and/or openings arranged therein communicating with pin receiving spaces to receive the corresponding pins located on the end surface of an opposing section each of said pin receiving spaces having metal walls and said pins having a transverse hole therethrough to receive a wedge device to be inserted through the hole in the pin via a transverse bore located through the side of the pile section, thereby to hold the opposing end surfaces of pile sections in firm abutting relationship. In previously known constructions, the wedge devices of the pile section locking joint are driven into the bores communicating with the and through the transverse holes in the pins with such force as to deform the wedge devices. This construction, however, has not proven sufficiently reliable in retaining the wedge devices in locking position. Several proposals have been made to reliably retain the wedge devices in position. One proposed solution includes a slot arranged on the point of the wedge device and a key to be placed in the slot so that as the wedge is driven into the bore and through the transverse hole in the pin, the end portions of the wedge located on either side of the slot are forced apart by the key. Another proposed solution has at the front end of the wedge device a locking pin capable of being moved into the interior of the wedge device, the locking pin when inserted into position being biased to force outward a locking device in the form of a steel ball located in a radial passage disposed in the wedge devices in a manner such that the ball engages the walls of the transverse extending hole on either side of the wedge devices. Neither of these solutions, however, have afforded a satisfactory result.

Since it is of the utmost importance that the joint structure securing the sections of a pile of the type described be such that the elements forming part of the joint do not become loose when subjected to the high forces occurring as the pile is driven into the ground, the object of the present invention is to provide a locking joint of the aforementioned type with which the wedge means are retained in their locking position in a reliable and efficient manner, using simple and inexpensive locking means.

This object is realized by the present invention which is mainly characterized in that the wedge device is held in locking position in the bore and in the transverse hole through the pin by mutually co-acting locking means located in the bore adjacent the side surface of the section and on the wedge device itself.

In accordance with a preferred embodiment of the invention, the co-acting locking elements include a reduced cross section step on the wedge device and a resilient annular ring of wavy or sinusoidal configuration about its periphery arranged to engage the step and accommodated in a circumferentially extending groove extending around the bore adjacent the side surface of the pile section. The wedge device may be constructed in a number of different ways, although it is preferred that it is provided with a bulged portion, the rear end surface of which can serve to form the aforementioned reduced cross section step and the front end of which can be tapered in a direction towards the point of the wedge device. With this construction, the forward end of the bulged portion acts to open up the resilient annular ring as the wedge device is inserted through the bore and into the transverse hole in the pin, the annular ring returning to its normal size after the bulge passes therethrough and, together with the reduced cross section step on the wedge, the ring provides means for retaining the wedge device in its correct, inserted position regardless of the various stresses and strains to which the locking joint is subjected. The circumferentially extending groove disposed around the transverse bore may be located at a greater or lesser distance inward from the side surface'of the pile, although the position of the groove in the bore must always correspond to the position of the step on the wedge device. It has been found particularly advantageous to arrange the circumferentially extending groove immediately adjacent to the side wall of the pile section where the side wall is a metal collar attached to the metallic end surface of the pole section. When the circumferentially extending groove is in this position, the reduced cross section step on the wedge device should be located in the rear end of the wedge device.

The invention will now be described in more detail with reference to an embodiment thereof illustrated in the accompanying drawings, of which FIG. 1 is a cross section of a joint between two pile sections according to the invention; and

FIG. 2 is an enlarged cross sectional view of a locking means of the joint shown in FIG. 1 and illustrates in dotted and solid lines further details of the invention.

As will be seen from FIG. 1, each of the end fittings 1,2 has a a metal plate 3, the thickness of which should be such as to provide a rigid joint. Secured by welding around the edge surface of the plate 3 is a collar 4, whereby each of the end fittings 1,2 forms a bowl shaped hollow for receiving the end of a pile section. Extending outward from the plates 3 are pins 5 which are welded to the plates 3 and to reinforcing rods 6 in the pile sections. Defined in the pins 5 are transversely extending holes 7 intended for receiving wedge devices 8. Attached by welding to the sides of the plates 3 are metal locking blocks 9.Defined in the locking blocks 9 and extending through the plates 3 are spaces 10 intended to receive the pins 5 located on the opposing plate 3. The metal plates 3 to which the locking blocks 9 are welded are relatively thin in the illustrated embodiment. However, it will be readily understood that with locking joints of the type envisioned, the plates 3 may be of such thickness as to permit the spaces 10 for the pins 5 to be arranged completely within the confines of the plate.

. Located in the locking blocks 9 are bores 12 which are accessible through openings 11 defined in the side surfaces of collar 4, the bores 12 intersecting and crossing the spaces 10 receiving the pins 5. The bores 12 are arranged to correspond to the transverse holes 7 in the pins 5.

The pins 5 and the locking block 9 are arranged alternately at equally spaced intervals equidistance from the centre of the plates. Thus, the same end fitting can be used for either ends of the pile sections being joined together.

Like the pins 5, the locking blocks 9 are welded to the reinforcing rods 6 in the pile sections. The reinforcing rods 6 in the pile sections are to be considered as auxiliary reinforcements. The main reinforcement (not shown) of the pile sections should extend through the sections as a whole and is preferably not connected directly to the metal plates 3 of the associated end fittings.

The wedge devices to be inserted through the transverse holes 7 through the pins 5 are inserted through the openings 11 into the bores 12 and through the holes 7 in the pins 5 until the ends of the wedge devices are located in the portion of the bore 12 situated beyond the pin receiving spaces 10 in the locking blocks 9. The wedge devices, which in the illustrated embodiment have the form of bolts which taper at their front end, are suitably driven into position in the manner illustrated to the left in FIG. 1. The hole 7 in the pins 5 and the bore 12 in the locking block 9 are, together with the wedge means 8, so designed that the wedge means, when driven into the joint, is deformed to provide a significant tension force on the associated pin 5 so that the two end sections 1 and 2 with associated pile sections are pulled into firm abutment engagement with each other.

The tension forces provided by deformation of the wedge devices or bolts 8, however, are not always sufficient to ensure that the wedge device is retained in its locking position. To insure that the wedge devices are held in position there are provided in accordance with the invention special co-acting locking elements arranged in the walls of the bore 12 and on the wedge means itself. Specifically, these co-acting locking elements include a reduced cross section step 13 on the wedge device and a resilient annular ring 14 located in a circumferentially extending groove 15 defined in the locking block 9 about the bore 12 and intended to engage the step 13. The annular ring 14 is retained in the groove 15 by the collar 4, the diameter of the opening 11 in the collar 4 being smaller than the outer diameter of the ring 14, but greater than its inner diameter to permit the wedge device to be inserted therethrough, while retaining the ring 14 in place. The cross section reducing step 13 on the wedge devices 8 is, in the illustrated embodiment, formed by the rear end of a flangelike bulged portion 16 on the wedge devices 8. The forward end of the bulged portion 16 is tapered towards the point of the wedge device to facilitate the passage of the wedge device 8 through the resilient annular ring 14 when the wedge device is inserted into the bore 12.

Practical tests have shown that when the cross section reducing step 13 engages the inside of the annular ring 14 in the groove 15, a wedge device is retained positively in its locking position under all conditions of stress to which it may be subjected during a pile driving operation, the inner diameter of the ring 14 being much less than the diameter of the bulged position 16. Hence, because of the wavy configuration of ring 14 certain raised portions about the periphery of the ring resiliently engage the reduced cross section step 13 on the bulged portion 16 of a wedge 8 in a direction longitudinally of bore 12 and positively retain the wedge under all conditions of stress in the bore in the manner illustrated in FIGS. 1-2.

The invention is not restricted to the described and illustrated embodiment but can be modified in many different ways within the scope of the following claims.

What I claim is:

1. A locking joint for joining first and second sections of a concrete pile comprising a metal plate on the end of each pile section,

a metal collar extending from the metal plate on a first pile section around said pile section, said collar having an opening defined therein,

a locking block secured behind the metal plate of the first pile section, said locking block having a longitudinal pin receiving space defined therein and also a transverse bore defined therein intersecting the pin receiving space and aligned with the opening in said collar,

an outwardly projecting pin projecting from the metal plate of the second pile section and received in the pin receiving space in said locking block, said pin having a transverse hole therethrough,

a wedge device having a front end and a rear end and projecting through the transverse bore in said locking block and through the hole in said pin to hold the metal plates in firm abutting relationship,

a bulged portion constructed on the rear end of said wedge device and having toward its front an inwardly tapered portion and at its rear having a reduced cross section step,

said locking block having defined therein a circumferentially extending groove around said bore and adjacent said collar, and

an annular resilient ring of wavy configuration about its periphery having an inner and an outer diameter, the outer diameter being greater than the diameter of the opening in said collar and the inner diameter being smaller than the diameter of the opening in said collar, said annular ring being accommodated in the groove in said locking block and being retained therein by said collar, certain raised portions about the periphery of said ring resiliently engaging said reduced cross section step on said wedge device in a direction longitudinally of the bore and positively retaining said wedge device under all conditions of stress in said bore. 

1. A locking joint for joining first and second sections oF a concrete pile comprising a metal plate on the end of each pile section, a metal collar extending from the metal plate on a first pile section around said pile section, said collar having an opening defined therein, a locking block secured behind the metal plate of the first pile section, said locking block having a longitudinal pin receiving space defined therein and also a transverse bore defined therein intersecting the pin receiving space and aligned with the opening in said collar, an outwardly projecting pin projecting from the metal plate of the second pile section and received in the pin receiving space in said locking block, said pin having a transverse hole therethrough, a wedge device having a front end and a rear end and projecting through the transverse bore in said locking block and through the hole in said pin to hold the metal plates in firm abutting relationship, a bulged portion constructed on the rear end of said wedge device and having toward its front an inwardly tapered portion and at its rear having a reduced cross section step, said locking block having defined therein a circumferentially extending groove around said bore adn adjacent said collar, and an annular resilient ring of wavy configuration about its periphery having an inner and an outer diameter, the outer diameter being greater than the diameter of the opening in said collar and the inner diameter being smaller than the diameter of the opening in said collar, said annular ring being accommodated in the groove in said locking block and being retained therein by said collar, certain raised portions about the periphery of said ring resiliently engaging said reduced cross section step on said wedge device in a direction longitudinally of the bore and positively retaining said wedge device under all conditions of stress in said bore. 